The present invention relates to light powered systems, and in particularly, to light powered remote systems and a power supply therefor. In remote systems, a sensor is typically located remote from its power supply and from the device monitoring the sensor's output. In electrically noisy environments, this physical separation practically ensures that the power supplied to the sensor will be noisy, causing the sensor to operate in an unknown and unpredictable manner. As a result, the sensor's output may not accurately reflect the parameter being sensed. This problem is compounded because the output of the sensor must also be routed through the electrically noisy environment, causing further noise to be added to the sensor's output.
One approach to the noise problem is to employ a power supply located close to the sensor. An example of such a power supply is found in battery powered sensors. However, batteries have limited lifetimes. This makes batteries unacceptable for many applications.
Another approach uses a remote power supply together with fiber optics to route the sensor's output to the device monitoring the output. This approach, however, solves only half of the problem.
An additional approach eliminates the power supply altogether, and employs passive or electromechanical sensors. A fiber optic links the passive sensor to the device monitoring its output. Such passive sensors alter some property of light so that a parameter can be detected, i.e., transduced. These passive sensors, however, are expensive and can be used only to measure a limited number of parameters.